Variable electric current generating device

ABSTRACT

Inside a sealed case there is a photoelectric core that is sensitive to ultraviolet radiations and that is provided with a multiplicity of openings communicating with its outside. Surrounding the core and filling its openings is a radioactive self-ionized isotopic fluid that produces ultraviolet radiations which activate the core to produce electric current.

Waited States Patent [191 Walker 1 Feb. 6, 1973 [5 1 VARIIAELE ELEQTRHCCURRENT 3,438,365 4/l969 Packer ct I ..250/l06 s x GENERATING DEVICE2.884.538 4/l959 Swift. Jr

2304.6l2. 9/l959 Re nicr ..I36/89 [761 memo" Wm Walker, 8 Earlswood3,031,519 4/1962 silv crman ..l36/89 Avenue, Pittsburgh, Pa. 15228 22Filed; March 23 1974 Primary ExaminerAllen B. Curtis AttorneyBrown,Murray, Flick & Peckham [21] Appl. N0.: 21,912

i ABSTRACT [52] 250/106 IMO/4 Inside a sealed case there is aphotoelectric core that [51] hit. Cl. is Sensitive to ultravioletradiations and that is p Fleld of Search l S; 3 vided a of p gcommunicating with its outside. Surrounding the core and filling its[56] References cued openings is a radioactive self-ionized isotopicfluid TE STATES PATENTS that produces ultraviolet radiations whichactivate the core to produce electric current. 3,497,392 2/1970 Walker..l36/89 3,093,567 6/1963 'Jablonski ..3 [0/4 X 9 Claims, 5 DrawingFigures 'PATENTEDFEB' 6M5 3.715.237

SHEET 2 BF 3 MIVIE/VTOR. By JOHN BLWAL/(BQ ATTORNEYS.

VARIABLE ELECTRIC CURRENT GENERATING DEVICE In my US. Pat. No.3,497,392, an electric current generating cell is disclosed in which afluid surrounding a core sensitive to ultraviolet radiations is ionizedby radioactive material which the core surrounds. The radiationsactivate the core to produce electric current that can be used for anydesired purpose. The current generating cell disclosed in that patent ishighly satisfactory in operation, but it does require radioactive sourcematerial such as strontium, plutonium, uranium or the like. Also, thecurrent output is not variable appreciably; it is either full on or fulloff.

It is an object of this invention to provide an electric currentgenerating device somewhat similar to my earlier one but not requiringradioactive source material. Another object is to provide such a devicethat is easily controlled for variable current output.

The preferred embodiment of the invention is illus-- trated in theaccompanying drawings, in which FIG. I is a side view of my device;

FIG. 2 is an enlarged fragmentary longitudinal section through a cellcase;

FIG. 3 is a still larger fragmentary longitudinal section, taken on theline III-III of FIG. 2;

FIG. 4 is an enlarged cross section taken on the line IV--IV of FIG. 2;and

FIG. 5 is an enlarged longitudinal section of the valves connected tothe cell case.

Referring to FIGS. 2 to 4 of the drawings, the cell case may be formedfrom a metal cylinder 1, on the opposite ends of which end bells 2 arescrewed, with sealing gaskets 3 compressed between the bells and the endflanges 4 of the cylindenEach'end bell is provided with a centralpassage, through which extends an electrical conductor in the form of astud 6 having a threaded outer end and a head 7 at its inner end. Thestud is centered in the passage by an insulating'bushing 8 that isclamped against the end of the bell by an end cap 9 screwed onto theouter end of the stud. Sealing washers 10 and 11 are compressed betweenthe bushing and the cap and bell. At the inner end of the bushing thereis a ring of sealing compound 12 and then another insulating bushing 13.The head of the stud is separated from the inside of the bell by twoplastic gaskets 14, between which there is an insulating washer 15.

The case contains a photoelectric core, which could be constructed inthe same way as the core in my earlier cell. It is preferred, however,to make the core in the form shown in FIGS. 2, 3 and 4. This coreincludes a stack of parallel rectangular panels 17 made of electricalinsulating material. These panels are spaced apart at their ends andcenter by thick spacers 18. The stack fits in a rectangular metalhousing 19 that is open at both ends. The upper and lower panels arespaced from the top and bottom of the housing by insulating spacers 20.Each panel is provided with a large number of perforations 22 andcarries between the perforations a plurality of cells 23 sensitive toultraviolet light. Preferably,.these cells are mounted in openings inthe panels and project from both sides of each panel. Each pair of cellscan be spaced apart or be separated by a spacer. The panels are spacedjust far enough apart to prevent the cells on each panel from touchingthose on the adjacent panels. The cells can be any of several varieties,such as selenium, silicon, cadmium and indium construction.

The cells are all electrically connected together in any suitablemanner. One way of doing this is to provide the panels with printedcircuits that the terminals of the cells engage. At the opposite ends ofthe panels the cells are connected by wires 24 to bus bars 25 thatextend across all of the panels centrally thereof. To support the busbars and also to help retain the panels in place, some or even all ofthe panels may be provided with central projections 26 at their ends,through which the bus bars extend snugly. The opposite ends of the barsare insulated from the surrounding metal housing by means of insulatingcaps 27. Each bus bar is elec trically connected to the head 7 of theadjacent stud by means of flexible conductors 28 attached thereto. Thecorners of metal housing 19 may engage the inner surface of thesurrounding case, but the space between the sides of the housing and thecase are filled with plastic fillers 31, that hold the housing in place.PLastic spacing blocks 32 are disposed in the ends of the metal housing.

In order to generate electricity, the cell case is filled with aradioactive self-ionized isotopic fluid, which of course fills thespaces between the panels as well as the perforations in them. Thisfluid produces ultraviolet radiations that activate cells 23 to causethem to produce electric current which is led off through the bus barsand the conductors 6 extending out of the end bells. The radioactivefluid may take several different forms. Any radioactive gas isotope thatproduces alpha or beta radiations and to which mercury vapor or benzene(C H is exposed can cause the desired ultraviolet radiations to beproduced. The isotope ionizes the mercury or benzene atoms to producethe radiations. For example, mercury vapor or benzene can be mixed withisotopes krypton 85, xenon 133, or argon 39. Although tritium H3 alsocould be used, it has the disadvantage of not being an inert gas.Instead of using a mixture of an .inert gas and mercury vapor, theradioactive mercury isotope Hg 203 can be used by itself to produce theultraviolet radiations. The photoelectric core is coated with a specialliquid plastic material impervious to alpha and beta particles but notto ultraviolet radiation.

By using one of the above fluids, radioactive source material can beeliminated from my current generating device and a better basis forcontrol is established. The control of the current generated by thisdevice is effected by controlling the pressure of the fluid in thesealed case. With a fixed pressure, a fixed level of current output isprovided, but if the pressure is increased the current will increase orif the pressure is reduced the current will decrease. This is becausecontrolling the pressure of the ionized fluid controls the amount ofultraviolet radiations that affect the sensitized core. Control can varyfrom a fully off to a fully on condition. Variation in the fluidpressure is accomplished by pumping the isotopic 'fluid in and out ofthe case.

As shown in FIG. 1, a single core-containing case can be used or two ormore can be electrically connected in parallel or series. Each case isprovided centrally with an opening, in which a valve 35 is screwed. Theinner end of the valve passage communicates with a passage 36 extendinglengthwise through the surrounding filler 31 so that the valve is incommunication with the inside of the end bells and therefore with thestack of panels. Each valve is connected by a short flexible hose 37 toa manifold 38, from'which a hose 39 extends to a T- fitting 40, the sideof which is connected to a solenoid valve 41 that leads to the inlet ofa pressure-vacuum pump 42 driven by a motor 43. The solenoid valve isopened when the motor is turned on. The outlet of the pump is connectedby a check valve 44 to a chamber'or tank 45 that has a solenoid outletvalve 46 connected with the remaining port of the T-fitting. Shut-offvalves 47 and 48 also are provided.

Connected i'nto manifold 38 is an electrically controlled automaticdifferential pressure control valve 50 that is electrically connectedwith the pump motor to shut if off when a predetermined vacuum isreached at the vacuum side of the valve. This valve also is electricallyconnected with solenoid valve 46 to close it when a predeterminedpressure is reached at the pressure side of valve 50. Valve 46 also canbe opened independently of valve 50,.so that if fluid at a pressureexceeding normal operating pressure is stored in tank 45, valve 46 canbe opened when desired to increase the pressure in the cell case abovethat called for by valve 50.

Valve 35 normally is open so that the cell case can be pressurized orthe pressure reduced in the case. Itis closed only when hose 37 isdisconnected from the case. The closed valve is designed to preventescape of fluid from both the case and the hose. For this purpose thevalve is constructed as shown in FIG. 5. It has a body 55 screwed intothe case and containing an interiorly tapered rubber cup 56 with aperforated top. Inside the cup there is a conical closure member 57pressed toward its seat by a coil spring 58 and having an upwardlyextending stem 59. Pressed against the upper end of the valve body by athreaded collar 61 is the lower end of another valve body 62 likewisecontaining another rubber cup 63 and a spring-pressed conical closuremember 64 provided with a downwardly extending stem 65. As long as thetwo valve bodies are pressed together by collar 61, the two valve stemsalso are pressed together with the result that the closure members areheld off their seats. On the other hand, if the collar is removed, theclosure members will be pressed against their seats by the coil springsand both the case and hose 37 will be sealed.

The system is evacuated and then charged through a special valve fitting70 connected to the top of storage tank 45. Before the radioactive fluidis delivered to the system the latter is evacuated by pump 42, the airbeing forced out of the system through the fitting. However, since thisdoes not evacuate the tank, the latter then is evacuated by aportablevacuum pump (not shown) which can also draw additional air outof the system by sucking the check valve 44 off its seat. of course,during this operation solenoid valve'4l, as well as manifold valves 47and 48, must be open and solenoid valve 46 closed. When the portablepump is turned off, solenoid valve 41 is closed and then the gas isotopefrom a pressure cylinder is connected with valve fitting 70 and the gasallowed to enter the storage tank. Check valve 44 prevents the pumpcircuit from After flooded with gas during charging and prevents backpressure during other pump phases. Mercury or benzene is drawn into thetank through the valve fitting along with the gas." AFter the tank hasbeen pressurized in this way with the radioactive self-ionized isotopicfluid to its proper predetermined level, the charging cylinder is shutoff and fitting is closed, followed by disconnection of the cylinderfrom the tank. The system now is ready to be activated.

Solenoid valve 46 now is opened by a manually operated electric switchto allow the radioactive fluid to expand and flow to the manifold andthrough valves 35 into the cell cases. As the fluid enters the cellcases 1 it expands further and flows into the photoelectric cores, whereit starts to activate the ultraviolet sensitized cells 23 to produce aflow of electric current that is detectable at the end caps 9 of theelectrical conductors.

The amount of current flow is determined by the fluid pressure in thecell cases. When the pressure reaches a preset level at the differentialcontrol valve 50, the electric circuit in that valve will close solenoidvalve 46. At that time the electric current output should be at its peakand should remain there as long as the fluid pressure in the cells holdsup. Lowering the current output of the cells is accomplished by turningon the vacuum pump motor 43 which opens valve 41 in the same circuit.The vacuum pump then pumps ionized fluid out of the cell cases andcompresses it in storage tank 45 for further use. The pump can bestopped at any time and yet the cell cores will continue to function,but at a lower rate of current flow.'lf all of the ionized fluid iswithdrawn from the cells, electric current production will be shut off.By increasing or decreasing the fluid pressure in the cell cases in themanner just explained, the current flow is controlled to any desiredlevel.

Starting up the cells or increasing the current flow is simply a matterof opening solenoid valve 46 to let the ultraviolet radiating ionizedfluid bleed back into the cell cases 1. Since the solenoid valve 41isclosed at that time, the fluid is prevented from feeding back into thepump. The differential pressure control valve 50 will close solenoid 46when the proper fluid pressure in the system is reached.

The electric circuit for solenoid valve 46 is such that it can be closedindependently of the differential control valve, so that a fluidpressure less than the maximum can be provided. This makes itunnecessary to first reach a maximum peak pressure and then pump down tothe pressure desired, thereby avoiding unnecessary use of the pump.Also, since valve 46 can be opened independently of the differentialcontrol valve, the pressure in the system can be increased above thelimit allowed by the control valve. This would be done only when theionization level of the fluid decreases relative to its radioactive halflife span. in this way the current output can be kept at a desiredmaximum in spite of the drop off of the radiation intensity of thefluid. However, there is a limit to this that is reached when theradiation level drops off to a point that increased fluid pressurecannot prevent a decline in current output. This may be arrived at nearthe half life of the radioactive isotope used.

-This electric current generating device can be used with a flxed fluidpressure to produce a fixed level of electric current. The cell casescan be placed in racks and connected in series or parallel, or they canbe used as portable auxiliary power units. 0n the other hand,

' the cells can produce a variable current output by automatically ormanually raising or lowering the fluid pressure in their cases. Thefeature of pumping the fluid in and out of the cell cases to controlcurrent flow or to shut it off lengthens the photoelectric core lifebecause it does not need to run at full power output at all times. Also,excess current does not have to be bled off. This method of operationand control also enables the cells to be used at low pressure due to thefact that the gas molecules in themselves are radioactive and do nothave to be ionized by collision of alpha or beta particles from aradioactive source material that makes it mandatory that the fluid to beionized be in a close compact condition with the radioactive sourcematerial at a set moderately high pressure.

At any time desired, the manually operated valves 47 can be closedsothat either photoelectric core can be shut down or either can beoperated at a different pres sure than the other. Also, a faulty circuitcan be removed by shutting off a valve 47 and disconnecting theadjoining hose 37 from its valve 35. The cells also can be placed in aparallel circuit without a change in the manifold. If a cell case isremoved from the manifold after being pressurized, the unit can be usedas a portable power pack or it can be shifted to another circuit ifdesired.

lclaim:

1. An electric current generating device comprising a sealed case, aphotoelectric core inside the case sensitive to ultraviolet radiationsand having therein a multiplicity of opening communicating with itsoutside, a radioactive self-ionized isotopic fluid surrounding the coreand filling its openings, said fluid producing ultraviolet radiationsthat activate the core to produce electric current, means electricallyconnected with said core and extending out of the case for conductingsaid current away from the photoelectric core, said photoelectric coreincluding a stack of spaced panels, and a plurality of ultraviolet lightsensitive cells mounted on both sides of each panel and electricallyconnected together.

2. An electric current generating device according to claim I, in whichsaid panels are provided with a multiplicity of perforations betweensaid cells. 4

3. An electric current generating device according to claim 1, includinga housing around said stack of panels but open at its ends, andinsulation between the housing and case.

4. An electric current generating device according to claim 1, in whicha bus bar at each end of said stack extends through projecting portionsof at least some of the panels, and wires connect the bus bars with thecells on each panel.

5. An electric current generating device comprising a sealed case, aphotoelectric core inside the case sensitive to ultraviolet radiationsand having therein a multiplicity of openings communicating with itsoutside, a radioactive self-ionized isotopic fluid surrounding the coreand filling its openings, said fluid producing ultraviolet radiationsthat activate the core to produce electric current, means electricallyconnected with said core and extending out of the case for conductingsaid current away from the photoelectric core, and means for varying thepressure of said fluid in said case to control the electrical output ofsaid core.

6. An electric current generating device according to claim 5, includinga storage chamber for said fluid outside of said case, a conduitconnecting the chamber with the inside of the case, saidpressure-varying means being means for pumping fluid through saidconduit from the case to said chamber to reduce the fluid pressure inthe case and increase the pressure in the chamber, and a valve forallowing flow of fluid from said chamber back through said conduit tothe case to increase the pressure therein.

7. An electric current generating device according to claim 6, includinga differential pressure control valve exposed to the fluid pressure insaid case for controlling said pumping means and first-mentioned valve.

8. An electric current generating device according to claim 5, in whichsaid core includes a plurality of ultraviolet light sensitive cellselectrically connected together, and means supporting the cells in aplurality of parallel layers with each layer containing a plurality ofthe cells.

9. An electric current generating device according to claim 5, in whichsaid fluid is a mixture of a radioactive gas isotope that producesradiations normally having a wave length outside the ultraviolet range,and another gas that shifts the wave length of said isotope radiationsso that said ultraviolet radiations are produced.

1. An electric current generating device comprising a sealed case, aphotoelectric core inside the case sensitive to ultraviolet radiationsand having therein a multiplicity of opening communicating with itsoutside, a radioactive self-ionized isotopic fluid surrounding the coreand filling its openings, said fluid producing ultraviolet radiationsthat activate the core to produce electric current, means electricallyconnected with said core and extending out of the case for conductingsaid current away from the photoelectric core, said photoelectric coreincluding a stack of spaced panels, and a plurality of ultraviolet lightsensitive cells mounted on both sides of each panel and electricallyconnected together.
 2. An electric current generating device accordingto claim 1, in which said panels are provided with a multiplicity ofperforations between said cells.
 3. An electric current generatingdevice according to claim 1, including a housing around said stack ofpanels but open at its ends, and insulation between the housing andcase.
 4. An electric current generating device according to claim 1, inwhich a bus bar at each end of said stack extends through projectingportions of at least some of the panels, and wires connect the bus barswith the cells on each panel.
 5. An electric current generating devicecomprising a sealed case, a photoelectric core inside the case sensitiveto ultraviolet radiations and having therein a multiplicity of openingscommunicating with its outside, a radioactive self-ionized isotopicfluid surrounding the core and filling its openings, said fluidproducing ultraviolet radiations that activate the core to produceelectric current, means electrically connected with said core andextending out of the case for conducting said current away from thephotoelectric core, and means for varying the pressure of said fluid insaid case to control the electrical output of said core.
 6. An electriccurrent generating device according to claim 5, including a storagechamber for said fluid outside of said case, a conduit connecting thechamber with the inside of the case, said pressure-varying means beingmeans for pumping fluid through said conduit from the case to saidchamber to reduce the fluid pressure in the case and increase thepressure in the chamber, and a valve for allowing flow of fluid fromsaid chamber back through said conduit to the case to increase thepressure therein.
 7. An electric current generating device according toclaim 6, including a differential pressure control valve exposed to thefluid pressure in said case for controlling said pumping means andfirst-mentioned valve.
 8. An electric current generating deviceaccording to claim 5, in which said core includes a plurality ofultraviolet light sensitive cells electrically connected together, andmeans supporting the cells in a plurality of parallel layers with eachlayer containing a plurality of the cells.